1. Field of the Invention
The present invention relates to a method for manufacturing an electro-optical panel for fabricating a protective material film for a color filter by droplet discharge, and a method for manufacturing an electronic device, as well as an electro-optical panel, an electro-optical apparatus, and an electronic apparatus.
2. Background Information
Liquid crystal panels and other electro-optical panels capable of displaying color have a substrate with a color filter to extract selectively light with a specific wavelength from the white light of a light source. Color filters are generally formed from a resin colored with R (red), G (green), and B (blue) pigments. A color filter protective film is then formed on the color filter for the purpose of protecting the color filter and smoothing the surface of the color filter.
Conventionally, color filter protective films are made by thin film fabrication methods typified by spin coating, but such methods have been wasteful in that 90 percent or greater of the color filter protective film is discarded. Also, since a color filter protective film material in liquid form is formed into a thin film by centrifugal force in spin coating, the color filter protective film material adheres to the back surface of the color filter substrate, and a step for washing the back surface of the color filter substrate has been required. This has been a cause of decreased productivity. Furthermore, since a color filter protective film material in liquid form is formed into a thin film by centrifugal force in spin coating, it has been difficult to adapt this technique to a color filter substrate with large dimensions.
In view of this, techniques have recently been proposed for applying color filter protective film materials by inkjet (droplet discharge) methods, as disclosed, for example, in Patent Literature 1 and 2.
Inkjet methods waste hardly any material because the color filter protective film material is discharged from a nozzle to the necessary location. Also, there is no need to wash the back surface of the color filter substrate because the color filter protective film material is accurately discharged to a specific position on the color filter substrate. Furthermore, it is possible to adapt this technique to a color filter substrate with large dimensions if the scanning range of the inkjet head is increased (see JP-A 9-329707 and 2002-189120).
However, inkjets discharge droplets from a tiny nozzle. Droplets can be applied at high density in the main scanning direction (the direction perpendicular to the direction of nozzle alignment) if the drive frequency of discharge is increased. However, since there is a limit to increasing the density of the nozzles, there is also a limit to applying droplets at high density in the direction of nozzle alignment (the auxiliary scanning direction). Accordingly, there are also methods in which droplets are applied at a high density by reducing the width of coating in the auxiliary scanning direction, but productivity decreases as a result.
It will be clear to those skilled in the art from the disclosure of the present invention that an improved method and apparatus for fabricating a functional film is necessary because of the above-mentioned considerations. The present invention meets the requirements of these conventional technologies as well as other requirements, which will be apparent to those skilled in the art from the disclosure hereinbelow.